How to intervene militarily

OXFORD, England — Because peacekeeping initiatives in postconflict countries are expensive and complex, and because the war in Iraq has undermined rich nations’ belief in their likely success, a dispassionate look at the use of military intervention is timely.

A new study for the Copenhagen Consensus project that includes the first ever cost-benefit analysis of U.N. peacekeeping initiatives concludes that military might is an important tool for reducing bloodshed around the world.

Iraq is a misleading guide to the effectiveness of such initiatives. Unlike the vast majority of conflicts, its civil war was sparked by an international war. The far more typical scenario is political violence within a small, low-income, low-growth nation burdened with strong ethnic divisions.

Dealing with these structurally dangerous countries is clearly one of our generation’s most pressing security challenges. There is good reason to think that trouble will escalate. Half of all civil wars are postconflict relapses, and recent negotiated peace settlements have left many countries unstable.

The commodity boom and the discovery of mineral resources in fragile states have sown seeds of discord, while the spread of democracy in low-income countries — perhaps surprisingly — increases the statistical likelihood of political violence.

Some believe that countries in conflict should be left to sort themselves out. But compassion and self-interest dictate against this approach. Modern civil wars are horrific. They overwhelmingly affect civilians in the poorest and most desperate environments on Earth.

Rich nations don’t fall victim to political violence, but do bear some of its costs. After all, broken societies are havens for illegality, whether drug trafficking or training of terrorists.

Military intervention won’t be the answer in every hot spot; nor should it be the developed world’s only response. Postconflict aid designed to prevent violence from recurring is much more politically acceptable than the use of force, although it is very expensive.

The period following a conflict is one of the most effective times to provide aid, because it enables governments to halt damaging inflationary policies and, with exports at a very low level, there is little risk of unwanted currency appreciation. With benefits about three times higher than the costs, it is a good — but not spectacular — use of scarce public resources.

The Copenhagen Consensus study recommends that aid to postconflict countries be tied to limits on military spending. Placing conditions on aid packages is controversial, but about 11 percent of all aid is currently diverted into military spending, which significantly increases the likelihood of violence. The lower risk of conflict and better use of that money would mean the benefits from aid climb to 4.5 times higher than the costs. Even so, the cost effectiveness of aid alone is outstripped by the use of peacekeeping forces.

The first cost-benefit analysis of peacekeeping initiatives reveals that the risk of future conflict depends upon the scale of military deployment. Compared with no deployment, spending $100 million on a peacekeeping initiative reduces the 10-year risk of conflict from around 38 percent to 16.5 percent. At $200 million per year, the risk falls further, to around 12.8 percent. At $500 million, it goes down to 9 percent, and at $850 million drops to 7.3 percent.

Because of war’s massive costs, each percentage point of risk reduction is worth around $2.5 billion to the world.

The most expensive deployment reduces the risk of conflict by a massive 30 percentage points, with 10-year gains of $75 billion, compared to the overall cost of $8.5 billion. This is a very promising investment.

Peacekeeping is an even better deal when it is provided in the form of an “over the horizon” security guarantee: a reliable commitment to dispatch troops if they are needed.

A guarantee could be offered by the United Nations or a regional power like the African Union to protect governments that came to power through certified democratic elections.

A guarantee could credibly help the world avoid three of the four new civil wars expected in low-income countries in each decade. The strategy could also safeguard postconflict societies after an initial period (of about five years) when the presence of troops is necessary.

Providing a credible security force to cope with all of these risks would cost about $2 billion annually, but the benefits — from a significant reduction in the risk of conflict and faster economic growth — are between 11.5 and 39 times higher.

Military intervention is not the only approach the world should use to reduce the incidence of political violence.

The best over-arching strategy is to combine aid, limits on military spending, peacekeeping forces, and “over the horizon” security guarantees in a way that ensures that the developed world deals with hot spots consistently. The U.N. Peace-Building Commission has the potential to coordinate this. The annual cost of the full package would be $10.8 billion, but the benefits to the world would be at least five times higher.

Controversy should not rule out the use of military force in situations where it will make a difference. Used as one part of a package, peacekeeping initiatives remain a reliable and effective way to provide stability to fragile nations and reduce the suffering of the world’s most vulnerable people.